Immune Mechanisms Underlying Neonatal Protection Following Maternal RSV Vaccination

Area of Science:

• Immunology
• Vaccinology
• Neonatal Health

Background:

• Respiratory syncytial virus (RSV) is a leading cause of severe infant respiratory infections.
• Infants possess immunological immaturity, limiting their intrinsic antiviral responses.
• Maternal vaccination offers a promising strategy for neonatal protection against RSV.

Purpose of the Study:

• To review mechanisms of maternally derived antibody-mediated neonatal protection against RSV.
• To elucidate the role of FcRn, IgG subclasses, and Fc glycosylation in antibody transfer and function.
• To identify factors influencing neonatal antibody levels and passive immunity duration.

Main Methods:

• Review of current literature on maternal RSV vaccination and neonatal immunity.
• Analysis of FcRn-mediated transplacental transport mechanisms.
• Examination of IgG subclass-specific transfer and half-life.
• Investigation of Fc glycosylation's role in Fcγ receptor interactions.

Main Results:

• Maternal vaccination induces high-titer, prefusion F-specific IgG1 antibodies for placental transfer.
• FcRn-mediated transport and IgG subclass influence antibody levels and persistence.
• Fc glycosylation impacts Fcγ receptor engagement and Fc-dependent effector functions.
• Both neutralization and Fc-dependent mechanisms contribute to neonatal protection.

Conclusions:

• Understanding antibody transport and effector functions is crucial for optimizing maternal RSV immunization.
• Factors like vaccination timing, antibody characteristics, and placental integrity are key determinants of neonatal immunity.
• Further research is needed to clarify selective placental transfer pathways and optimize strategies for early-life protection.